Liquid crystal displays, which are used in various fields, have some inherent viewing angle characteristics due to their principles. Thus, there is a demand for wider viewing angle characteristics.
For example, there are methods of widening the viewing angle characteristics of a liquid crystal display by selecting the pattern of the arrangement of liquid crystal molecules in a liquid crystal cell. For example, display modes such as TN mode, STN mode, IPS mode, and VA mode are proposed. These modes differ in their viewing angle characteristics and each have a merit and a demerit.
The viewing angle characteristics of liquid crystal displays are significantly influenced by a combination of the absorption axis of a polarizer and the direction of the orientation of liquid crystal molecules in a liquid crystal cell or by the retardation of a liquid crystal cell, or the like. In view of these matters, there are methods for widening the viewing angle characteristics of a liquid crystal display by the use of an optical compensation film that provides visibility for a liquid crystal panel.
A variety of optical compensation films are proposed such as products based on a retardation film using a polymer material such as polycarbonate and products using a liquid crystal polymer film. Examples of the liquid crystal polymer film include a twisted retardation film in which liquid crystal molecules are twisted with respect to the in-plane direction of the film and a product using a discotic or nematic liquid crystal that has uniaxiality to a certain extent with respect to the direction of the normal to the film plane and also has a specific tilt angle with respect to its cross-sectional direction. In particular, the discotic liquid crystal, which is a material exhibiting optically negative uniaxiality, is used and obliquely oriented to form an optical compensation film. A specific example of such a film is WV Film manufactured by Fuji Photo Film Co., Ltd. The optical compensation film using the discotic liquid crystal has been used as a viewing angle-widening film in TFT type liquid crystal displays or the like using a TN (90° twist) mode liquid crystal cell to improve the viewing angle characteristics of liquid crystal displays (for example, see Patent Literatures 1 and 2 below).
In the case where the optical film using the discotic liquid crystal is used in liquid crystal displays, with respect to the direction of the normal to the screen, the viewing angle characteristics can be widened in the lateral direction, but the widening of the viewing angle characteristics in the vertical direction (particularly in the downward (lower) direction) is not sufficient. In general, the optical film using the discotic liquid crystal is also unsatisfactory for the color shift to yellow in the film.    Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 2001-91745    Patent Literature 2: JP-A No. 2002-90527